National Climatic Data Center
14 February 2008
The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. The most current data may be accessed via the Global Surface Temperature Anomalies page.
Temperature anomalies for January 2008 are shown on the dot maps below. The dot map, below left, provides a spatial representation of anomalies calculated from the Global Historical Climatology Network (GHCN) data set of land surface stations using a 1961-1990 base period. The dot map, below right, is a product of a merged land surface and sea surface temperature anomaly analysis developed by Smith and Reynolds (2005). Temperature anomalies with respect to the 1961-1990 mean for land and ocean are analyzed separately and then merged to form the global analysis. Additional information on this product is available.
During January 2008, there were above average temperatures across Europe, northern Asia, the eastern parts of the contiguous U.S, and most of Australia. According to the Bureau of Meteorology (BoM), Australia had its warmest January on record. Temperatures were 3-4°C (5-7°F) above average across large areas in Western and Central Australia. The January 2008 average temperature for the nation was 1.23°C (2.21°F) above the 1961-1990 mean, which exceeded the previous anomaly record of +1.16°C (+2.09°F) set in January 1999. Elsewhere, cooler-than-average conditions occurred in the Middle East, central Asia, southeast China, the western U.S., and western Alaska. The anomalously cool conditions over central Asia and southeast China were associated with the largest January snow cover extent on record for the Eurasian continent and for the Northern Hemisphere.
Sea surface temperatures (SSTs) were warmer than average in the Atlantic, Indian, and the northwestern Pacific oceans. Cooler-than-average conditions were present in the southern oceans and in the Niño regions. Temperatures in parts of these Niño regions were more than 1°C (1.8°F) below average, and the average temperature in the Niño 3.4 region decreased markedly in January to approximately -1.77°C (-3.19°F). Please see the latest ENSO discussion for additional information.
The mean position of the upper level ridges of high pressure and troughs of low pressure (depicted by positive and negative 500-millibar height anomalies on the January map) are generally reflected by areas of positive and negative temperature anomalies at the surface, respectively. For other Global products see the Climate Monitoring Global Products page.
Images of sea surface temperature conditions are available for all weeks during 2008 at the weekly SST page.
Effective with the February 2006 report, NCDC transitioned from the use of the Operational Global Surface Temperature Index (Quayle et al. 1999) to the blended land and ocean dataset developed by Smith and Reynolds (2005). The differences between the two methods are discussed in Smith et al. (2005).
January 2008 ranked as the thirty-first warmest January since records began in 1880 for combined global land and ocean surface temperatures. Temperatures were colder than average across large parts of central Asia and southeastern China. The January global land surface average was below the 20th century mean for the first time since 1982. La Niña, the cold phase of the El Niño-Southern Oscillation, persisted in the equatorial Pacific, damping ocean surface temperatures. The global average ocean surface temperature (SST) in January was the seventeenth warmest on record.
| January | Anomaly | Rank | Warmest (or Next Warmest) Year on Record |
|---|---|---|---|
GlobalLandOcean Land and Ocean |
-0.01°C (-0.02°F) +0.25°C (+0.45°F) +0.18°C (+0.32°F) |
63rd warmest 17th warmest 31st warmest |
2007 (+1.84°C/3.31°F) 1998 (+0.52°C/0.94°F) 2007 (+0.83°C/1.49°F) |
Northern HemisphereLandOcean Land and Ocean |
-0.17°C (-0.31°F) +0.26°C (+0.47°F) +0.10°C (+0.18°F) |
70th warmest (60th coolest) 13th warmest 48th warmest |
2007 (+2.23°C/4.01°F) 1998 (+0.51°C/0.92°F) 2007 (+1.14°C/2.05°F) |
Southern HemisphereLandOcean Land and Ocean |
+0.48°C (+0.86°F) +0.24°C (+0.43°F) +0.28°C (+0.50°F) |
12th warmest 29th warmest 21st warmest |
2006 (+0.77°C/1.39°F) 1998 (+0.55°C/0.99°F) 1998 (+0.58°C/1.04°F) |
The most current data may be accessed via the Global Surface Temperature Anomalies page.
The maps below represent anomaly values based on the GHCN data set of land surface stations using a base period of 1961-1990. During January 2008, above average precipitation fell over areas that include England, northern Europe, eastern Australia, southeastern China, and parts of South America. Drier-than-average conditions were observed in Japan, southern Europe, the western coast of Canada, the eastern and central U.S., and most of western Australia. Additional details on flooding and drought can also be found on the January Global Hazards page.
Sea Surface Temperature (SST) anomalies continued to decrease across the central and western equatorial Pacific during January with cooler anomalies extending further west of the International Date Line. These conditions are indicative of a strong ENSO cold event (shown in the adjacent animation of weekly SST anomalies). A comprehensive summary of January 2008 ENSO conditions can be found on the ENSO monitoring page. For the latest advisory on ENSO conditions go to NOAA's Climate Prediction Center (CPC) and the CPC ENSO Diagnostic Discussion.
Images of sea surface temperature conditions are available for all weeks since 2003 at the weekly SST page.
As shown in the time series to the right, mean Northern Hemisphere snow cover extent during January 2008 was much above average. This can be attributed to a series of snow storms that struck much the Northern Hemisphere during the month of January. The January 2008 snow cover extent was the largest extent over the 42-year historical record, surpassing the previous record set in 1985. The mean Northern Hemisphere January snow cover extent for the 1967-2008 period of record is 47.0 million square kilometers.
Snow cover for January 2008 across North America was above average, being the 13th largest extent since records began in 1967. During the month of January, much of the contiguous U.S. experienced a series of snow storms. The mean North American January snow cover extent is 17.5 million square kilometers for the 1967-2008 period of record.
As depicted in the time series to the right, Eurasia's snow cover extent in January was much above average and was the largest extent over the 42-year historical period. During January, severe winter weather brought freezing temperatures and heavy snow across much of China and central Asia. In some areas, snow fell for the first time in living memory. On average, Eurasian January snow cover extent is 29.4 million square kilometers for the 1967-2008 period of record.
Data were provided by the Global Snow Laboratory, Rutgers University.
According to the National Snow and Ice Data Center, the January 2008 Northern Hemisphere sea ice extent, which is measured from passive microwave instruments onboard NOAA satellites, was below the 1979-2000 mean, but greater than the previous four years. Sea ice extent for January has decreased at a rate of 3.2%/decade (since satellite records began in 1979) as temperatures in the high latitude Northern Hemisphere have risen at a rate of approximately 0.37°C/decade over the same period.
Meanwhile, the January 2008 Southern Hemisphere sea ice extent was much above the 1979-2000 mean. This was the largest sea ice extent in January over the 30-year historical period. Sea ice extent for January has increased at a rate of 1.9%/decade.
For further information on the Northern and Southern Hemisphere snow and ice conditions, please visit the NSIDC News page, provided by the NOAA's National Snow and Ice Data center (NSIDC).
Temperatures above the Earth's surface are measured within the lower troposphere, middle troposphere, and stratosphere using in-situ balloon-borne instruments (radiosondes) and polar-orbiting satellites (NOAA's TIROS-N). The radiosonde and satellite records have been adjusted to remove time-dependent biases (artificialities caused by changes in radiosonde instruments and measurement practices as well as changes in satellite instruments and orbital features through time).
Note: January's report contains troposphere data from satellites only. The in-situ measurements will return in the February 2008 report.
These temperatures are for the lowest 8 km (5 miles) of the atmosphere. Information on the UAH and RSS sources of troposphere data is available.
| January | Anomaly | Rank | Warmest (or Next Warmest) Year on Record | Trend |
|---|---|---|---|---|
| UAH low-trop | -0.05°C/-0.09°F | 21st warmest (10th coolest) |
2007 (+0.59°C/1.06°F) | +0.16°C/decade |
| *RSS low-trop | -0.08°C/-0.14°F | 23rd warmest (8th coolest) |
1998 (+0.62°C/1.12°F) | +0.17°C/decade |
*Version 03_0
These temperatures are for the atmospheric layer centered in the mid-troposphere (approximately 3-10 km (2-6 miles) above the Earth's surface), which also includes a portion of the lower stratosphere. (The MSU channel used to measure mid-tropospheric temperatures receives about 25 percent of its signal above 10 km (6 miles)). Because the stratosphere has cooled due to increasing greenhouse gases in the troposphere and losses of ozone in the stratosphere, the stratospheric contribution to the tropospheric average, as measured from satellites, may create an artificial component of cooling to the mid-troposphere temperatures. The University of Washington (UW) versions of the UAH and RSS analyses attempt to remove the stratospheric influence from the mid-troposphere measurements, and as a result, the UW versions tend to have a larger warming trend than either the UAH or RSS versions. For additional information, please see NCDC's Microwave Sounding Unit page.
The global mid-troposphere temperatures were cooler than average in January 2008, as shown in the table below. Satellite measurement for January 2008 ranked from twentieth (eleventh) to twenty-fifth (sixth) warmest (coolest) on record, depending on the analysis.
| January | Anomaly | Rank | Warmest (or Next Warmest) Year on Record | Trend |
|---|---|---|---|---|
| UAH mid-trop | -0.18°C/-0.32°F | 25th warmest (6th coolest) |
1998 (+0.50°C/0.90°F) | +0.05°C/decade |
| *RSS mid-trop | -0.12°C/-0.21°F | 23rd warmest (8th coolest) |
1998 (+0.54°C/0.97°F) | +0.11°C/decade |
| **UW-UAH mid-trop | -0.11°C/-0.20°F | 22nd warmest (9th coolest) |
1998 (+0.64°C/1.15°F) | +0.12°C/decade |
| **UW-*RSS mid-trop | -0.05°C/-0.97°F | 20th warmest (11th coolest) |
1998 (+0.66°C1.19°F) | +0.17°C/decade |
*Version 03_0
The table below summarizes stratospheric conditions for January 2008. On average, the stratosphere is located approximately between 16-23 km (10-14 miles) above the Earth's surface. Over the last decade, stratospheric temperatures have been below average, in part due to the depletion of ozone. The large positive anomaly in 1982 was caused by the volcanic eruption of El Chichon in Mexico, and the sharp jump in temperature in 1991 was a result of the eruption of Mt. Pinatubo in the Philippines. In both cases the temperatures returned to pre-eruption levels within two years.
| January | Anomaly | Rank | Coolest Year on Record |
|---|---|---|---|
| UAH stratosphere | -0.58°C (-1.04°F) | 8th coolest | 2006 (-0.80°C/-1.44°F) |
| *RSS stratosphere | -0.50°C (-0.90°F) | 8th coolest | 2006 (-0.77°C/-1.39°F) |
*Version 03_0
For additional details on precipitation and temperatures in January, see the Global Hazards page.
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For all climate questions, other than questions concerning this report, please contact the National Climatic Data center's Climate Services Division:
Climate Services DivisionFor questions about this report, please contact:
Jay Lawrimore-or-
David Easterling
http://lwf.ncdc.noaa.gov/oa/climate/research/2008/jan/global.html 
